32
32
Jun 25, 2018
06/18
by
R. Buta; K. Sheth; E. Athanassoula; A. Bosma; J. Knapen; E. Laurikainen; H. Salo; D. Elmegreen; L. Ho; D. Zaritsky; H. Courtois; J. Hinz; J-C. Muñoz-Mateos; T. Kim; M. Regan; D. Gadotti; A. Gil de Paz; J. Laine; K. Menendez-Delmestre; Sebastien Comeron; S. Erroz Ferrer; M. Seibert; T. Mizusawa; B. Holwerda; B. Madore
texts
eye 32
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The Spitzer Survey of Stellar Structure in Galaxies (S4G) is the largest available database of deep, homogeneous middle-infrared (mid-IR) images of galaxies of all types. The survey, which includes 2352 nearby galaxies, reveals galaxy morphology only minimally affected by interstellar extinction. This paper presents an atlas and classifications of S4G galaxies in the Comprehensive de Vaucouleurs revised Hubble-Sandage (CVRHS) system. The CVRHS system follows the precepts of classical de...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics, Astrophysics
Source: http://arxiv.org/abs/1501.00454
14
14
Jun 25, 2018
06/18
by
B. M. Gaensler; Iván Agudo; Takuya Akahori; Julie Banfield; Rainer Beck; Ettore Carretti; Jamie Farnes; Marijke Haverkorn; George Heald; David Jones; Thomas Landecker; Sui Ann Mao; Ray Norris; Shane O'Sullivan; Lawrence Rudnick; Dominic Schnitzeler; Nicholas Seymour; Xiaohui Sun
texts
eye 14
favorite 0
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Faraday rotation of polarised background sources is a unique probe of astrophysical magnetic fields in a diverse range of foreground objects. However, to understand the properties of the polarised sources themselves and of depolarising phenomena along the line of sight, we need to complement Faraday rotation data with polarisation observations over very broad bandwidths. Just as it is impossible to properly image a complex source with limited u-v coverage, we can only meaningfully understand...
Topics: Cosmology and Nongalactic Astrophysics, Astrophysics, Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1501.00626
10
10.0
Jun 25, 2018
06/18
by
R. E. A. Canning; G. J. Ferland; A. C. Fabian; R. M. Johnstone; P. A. M. van Hoof; R. L. Porter; N. Werner; R. J. R. Williams
texts
eye 10
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Many massive galaxies at the centres of relaxed galaxy clusters and groups have vast reservoirs of cool (~10,000 K) and cold (~100 K) gas. In many low redshift brightest group and cluster galaxies this gas is lifted into the hot ISM in filamentary structures, which are long lived and are typically not forming stars. Two important questions are how far do these reservoirs cool and if cold gas is abundant what is the cause of the low star formation efficiency? Heating and excitation of the...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics, Astrophysics
Source: http://arxiv.org/abs/1501.01081
26
26
Jun 25, 2018
06/18
by
Manda Banerji; S. Alaghband-Zadeh; Paul C. Hewett; Richard G. McMahon
texts
eye 26
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We present a new population of z>2 dust-reddened, Type 1 quasars with 0.510^{13}L_0), high-redshift dusty quasars to 38. There is no evidence for reddened quasars having significantly different H$\alpha$ equivalent widths relative to unobscured quasars. The average black-hole masses (~10^9-10^10 M_0) and bolometric luminosities (~10^{47} erg/s) are comparable to the most luminous unobscured quasars at the same redshift, but with a tail extending to very high luminosities of ~10^{48} erg/s....
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics, Astrophysics
Source: http://arxiv.org/abs/1501.00815
20
20
Jun 25, 2018
06/18
by
F. de Gasperin; G. A. Ogrean; R. J. van Weeren; W. A. Dawson; M. Brüggen; A. Bonafede; A. Simionescu
texts
eye 20
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Extended steep-spectrum radio emission in a galaxy cluster is usually associated with a recent merger. However, given the complex scenario of galaxy cluster mergers, many of the discovered sources hardly fit into the strict boundaries of a precise taxonomy. This is especially true for radio phoenixes that do not have very well defined observational criteria. Radio phoenixes are aged radio galaxy lobes whose emission is reactivated by compression or other mechanisms. Here, we present the...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics, Astrophysics
Source: http://arxiv.org/abs/1501.00043
17
17
Jun 25, 2018
06/18
by
A. Popping; M. Meyer; L. Staveley-Smith; D. Obreschkow; G. I. Jozsa; D. J. Pisano
texts
eye 17
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The interaction of galaxies with their environment, the Intergalactic Medium (IGM), is an important aspect of galaxy formation. One of the most fundamental, but unanswered questions in the evolution of galaxies is how gas circulates in and around galaxies and how it enters the galaxies to support star formation. We have several lines of evidence that the observed evolution of star formation requires gas accretion from the IGM at all times and on all cosmic scales. This gas remains largely...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics, Astrophysics
Source: http://arxiv.org/abs/1501.01077
81
81
Jun 25, 2018
06/18
by
Shadab Alam; Franco D. Albareti; Carlos Allende Prieto; F. Anders; Scott F. Anderson; Brett H. Andrews; Eric Armengaud; Éric Aubourg; Stephen Bailey; Julian E. Bautista; Rachael L. Beaton; Joseph Huehnerhoff; Linhua Jiang; Jennifer A. Johnson; Karen Kinemuchi; David Kirkby; Francisco Kitaura; Mark A. Klaene; Jean-Paul Kneib; Xavier P. Koenig; Charles R. Lam; Timothy C. Beers; Ting-Wen Lan; Dustin Lang; Pierre Laurent; Jean-Marc Le Goff; Alexie Leauthaud; Khee-Gan Lee; Young Sun Lee; Timothy C....
texts
eye 81
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The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired...
Topics: Instrumentation and Methods for Astrophysics, Astrophysics, Astrophysics of Galaxies, Astrophysics,...
Source: http://arxiv.org/abs/1501.00963
22
22
Jun 25, 2018
06/18
by
Martin Meyer; Aaron Robotham; Danail Obreschkow; Simon Driver; Lister Staveley-Smith; Martin Zwaan
texts
eye 22
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The science achievable with SKA HI surveys will be greatly increased through the combination of HI data with that at other wavelengths. These multiwavelength datasets will enable studies to move beyond an understanding of HI gas in isolation to instead understand HI as an integral part of the highly complex baryonic processes that drive galaxy evolution. As they evolve, galaxies experience a host of environmental and feedback influences, many of which can radically impact their gas content....
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics, Astrophysics
Source: http://arxiv.org/abs/1501.01082
29
29
Jun 25, 2018
06/18
by
Hanno Rein
texts
eye 29
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The multi-planetary system HD128311 hosts at least two planets. Its dynamical formation history has been studied extensively in the literature. We reanalyse the latest radial velocity data for this system with the affine-invariant Markov chain Monte Carlo sampler EMCEE. Using the high order integrator IAS15, we perform a fully dynamical fit, allowing the planets to interact during the sampling process. A stability analysis using the MEGNO indicator reveals that the system is located in a stable...
Topics: Earth and Planetary Astrophysics, Astrophysics, Instrumentation and Methods for Astrophysics,...
Source: http://arxiv.org/abs/1501.00980
20
20
Jun 25, 2018
06/18
by
Jorge I. Zuluaga; Paul A. Mason; Pablo A. Cuartas
texts
eye 20
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comment 0
The discovery of many planets using the Kepler telescope includes ten planets orbiting eight binary stars. Three binaries, Kepler-16, Kepler-47, and Kepler-453, have at least one planet in the circumbinary habitable-zone (BHZ). We constrain the level of high-energy radiation and the plasma environment in the BHZ of these systems. With this aim, BHZ limits in these Kepler binaries are calculated as a function of time, and the habitability lifetimes are estimated for hypothetical terrestrial...
Topics: Earth and Planetary Astrophysics, Astrophysics, Solar and Stellar Astrophysics, Astrophysics
Source: http://arxiv.org/abs/1501.00296
26
26
Jun 25, 2018
06/18
by
J. Singal; A. Kogut; E. Jones; H. Dunlap
texts
eye 26
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We use surface brightness contour maps of nearby edge-on spiral galaxies to determine whether extended bright radio halos are common. In particular, we test a recent model of the spatial structure of the diffuse radio continuum by Subrahmanyan and Cowsik which posits that a substantial fraction of the observed high-latitude surface brightness originates from an extended Galactic halo of uniform emissivity. Measurements of the axial ratio of emission contours within a sample of normal spiral...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics, Astrophysics
Source: http://arxiv.org/abs/1501.00499
32
32
Jun 25, 2018
06/18
by
Gabriele Giovannini; Annalisa Bonafede; Shea Brown; Luigina Feretti; Chiara Ferrari; Myriam Gitti; Federica Govoni; Matteo Murgia; Valentina Vacca
texts
eye 32
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The presence of magnetic fields in galaxy clusters has been well established in recent years, and their importance for the understanding of the physical processes at work in the Intra Cluster Medium has been recognized. Halo and relic sources have been detected in several tens clusters. A strong correlation is present between the halo and relic radio power and the X-ray luminosity. Since cluster X-Ray luminosity and mass are related, the correlation between the radio power and X-ray luminosity...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics, Astrophysics
Source: http://arxiv.org/abs/1501.01023
11
11
Jun 25, 2018
06/18
by
Shaohua Zhang; Hongyan Zhou; Tinggui Wang; Huiyuan Wang; Xiheng Shi; Bo Liu; Wenjuan Liu; Zhenzhen Li; Shufen Wang
texts
eye 11
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We present the variability study of broad absorption lines (BALs) in a uniformly radio-selected sample of 28 BAL quasars using the archival data from the FIRST Bright Quasar Survey (FBQS) and the Sloan Digital Sky Survey (SDSS), as well as those obtained by ourselves, covering time scales $\sim 1-10$ years in the quasar's rest-frame. To our surprise, 5 quasars showing strong variations are all belong to a special subclass of overlapping iron low ionization BAL (OFeLoBAL) quasars, however, other...
Topics: Astrophysics of Galaxies, Astrophysics, Cosmology and Nongalactic Astrophysics, Astrophysics
Source: http://arxiv.org/abs/1501.00091
12
12
Jun 30, 2018
06/18
by
M. R. Schmidt; J. Krełowski; G. A. Galazutdinov; D. Zhao; M. A. Haddad; W. Ubachs; H. Linnartz
texts
eye 12
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We report the detection of eight vibronic bands of C$_3$, seven of which have been hitherto unobserved in astrophysical objects, in the translucent cloud towards HD~169454. Four of these bands are also found towards two additional objects: HD~73882 and HD~154368. Very high signal-to-noise ratio ($\sim$1000 and higher) and high resolving power ($R=80,000$) UVES-VLT spectra (Paranal, Chile) allow for detecting novel spectral features of C$_3$, even revealing weak perturbed features in the...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1403.7280
5
5.0
Jun 30, 2018
06/18
by
Seppo Laine; Johan H. Knapen; Juan-Carlos Munoz-Mateos; Taehyun Kim; Sebastien Comeron; Marie Martig; Benne W. Holwerda; E. Athanassoula; Albert Bosma; Peter H. Johansson; Santiago Erroz-Ferrer; Dimitri A. Gadotti; Armando Gil de Paz; Joannah Hinz; Jarkko Laine; Eija Laurikainen; Karin Menendez-Delmestre; Trisha Mizusawa; Michael W. Regan; Heikki Salo; Kartik Sheth; Mark Seibert; Ronald J. Buta; Mauricio Cisternas; Bruce G. Elmegreen; Debra M. Elmegreen; Luis C. Ho; Barry F. Madore; Dennis...
texts
eye 5
favorite 0
comment 0
We present a catalogue and images of visually detected features, such as asymmetries, extensions, warps, shells, tidal tails, polar rings, and obvious signs of mergers or interactions, in the faint outer regions (at and outside of R_25) of nearby galaxies. This catalogue can be used in future quantitative studies that examine galaxy evolution due to internal and external factors. We are able to reliably detect outer region features down to a brightness level of 0.03 MJy/sr per pixel at 3.6...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1408.2602
7
7.0
Jun 30, 2018
06/18
by
Shmuel Bialy; Amiel Sternberg
texts
eye 7
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We present numerical computations and analytic scaling relations for interstellar ion-molecule gas phase chemistry down to very low metallicities ($ 10^{-3} \times$ solar), and/or up to high driving ionization rates. Relevant environments include the cool interstellar medium (ISM) in low-metallicity dwarf galaxies, early enriched clouds at the reionization and Pop-II star formation era, and in dense cold gas exposed to intense X-ray or cosmic-ray sources. We focus on the behavior for H$_2$, CO,...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1409.6724
12
12
Jun 26, 2018
06/18
by
Katherine Hollyhead; Nate Bastian; Angela Adamo; Esteban Silva-Villa; Jim Dale; Jenna Ryon; Zack Gazak
texts
eye 12
favorite 0
comment 0
The study of young massive clusters can provide key information for the formation of globular clusters, as they are often considered analogues. A currently unanswered question in this field is how long these massive clusters remain embedded in their natal gas, with important implications for the formation of multiple populations that have been used to explain phenomena observed in globular clusters. We present an analysis of ages and masses of the young massive cluster population of M83....
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1502.03823
3
3.0
Jun 28, 2018
06/18
by
Joachim Janz; Mark A. Norris; Duncan A. Forbes; Avon Huxor; Aaron J. Romanowsky; Matthias J. Frank; Carlos G. Escudero; Favio R. Faifer; Juan Carlos Forte; Sheila J. Kannappan; Claudia Maraston; Jean P. Brodie; Jay Strader; Bradley R. Thompson
texts
eye 3
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In recent years, a growing zoo of compact stellar systems (CSSs) have been found whose physical properties (mass, size, velocity dispersion) place them between classical globular clusters (GCs) and true galaxies, leading to debates about their nature. Here we present results using a so far underutilised discriminant, their stellar population properties. Based on new spectroscopy from 8-10m telescopes, we derive ages, metallicities, and [\alpha/Fe] of 29 CSSs. These range from GCs with sizes of...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1511.03264
4
4.0
Jun 28, 2018
06/18
by
Vera Patrício; Johan Richard; Anne Verhamme; Lutz Wisotzki; Jarle Brinchmann; Monica L. Turner; Lise Christensen; Peter M. Weilbacher; Jérémy Blaizot; Roland Bacon; Thierry Contini; David Lagattuta; Sebastiano Cantalupo; Benjamin Clément; Geneviève Soucail
texts
eye 4
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Spatially resolved studies of high redshift galaxies, an essential insight into galaxy formation processes, have been mostly limited to stacking or unusually bright objects. We present here the study of a typical (L$^{*}$, M$_\star$ = 6 $\times 10^9$ $M_\odot$) young lensed galaxy at $z=3.5$, observed with MUSE, for which we obtain 2D resolved spatial information of Ly$\alpha$ and, for the first time, of CIII] emission. The exceptional signal-to-noise of the data reveals UV emission and...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1512.01212
5
5.0
Jun 29, 2018
06/18
by
Bengt Gustafsson; Ross Church; Melvyn B. Davies; Hans Rickman
texts
eye 5
favorite 0
comment 0
Could the velocity spread, increasing with time, in the Galactic disk be explained as a result of gravitational interactions of stars with giant molecular clouds (GMCs) and spiral arms? Do the old open clusters high above the Galactic plane provide clues to this question? We explore the effects on stellar orbits of scattering by inhomogeneities in the Galactic potential due to GMCs, spiral arms and the Galactic bar, and whether high-altitude clusters could have formed in orbits closer to the...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1605.02965
5
5.0
Jun 30, 2018
06/18
by
Oli L. Dors; Monica V. Cardaci; Guillermo F. Hagele; Angela C. Krabbe
texts
eye 5
favorite 0
comment 0
We analyzed the evolution of the metallicity of the gas with the redshift for a sample of AGNs in a very wide redshift range (0
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1406.4832
6
6.0
Jun 27, 2018
06/18
by
A. V. Ivlev; T. B. Röcker; A. Vasyunin; P. Caselli
texts
eye 6
favorite 0
comment 0
The problem of impulsive heating of dust grains in cold, dense interstellar clouds is revisited theoretically, with the aim to better understand leading mechanisms of the explosive desorption of icy mantles. It is rigorously shown that if the heating of a reactive medium occurs within a sufficiently localized spot (e.g., heating of mantles by cosmic rays), then the subsequent thermal evolution is characterized by a single dimensionless number $\lambda$. This number identifies a bifurcation...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1503.05012
15
15
Jun 28, 2018
06/18
by
H. Ikeda; T. Nagao; Y. Taniguchi; K. Matsuoka; M. Kajisawa; M. Akiyama; T. Miyaji; N. Kashikawa; T. Morokuma; Y. Shioya; M. Enoki; P. Capak; A. M. Koekemoer; D. Masters; M. Salvato; D. B. Sanders; E. Schinnerer; N. Z. Scoville
texts
eye 15
favorite 0
comment 0
In order to investigate the origin of quasars, we estimate the bias factor for low-luminosity quasars at high redshift for the first time. In this study, we use the two-point angular cross-correlation function (CCF) for both low-luminosity quasars at $-24
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1507.05292
14
14
Jun 28, 2018
06/18
by
Manda Banerji; R. G. McMahon; C. J. Willott; J. E. Geach; C. M. Harrison; S. Alaghband-Zadeh; D. M. Alexander; N. Bourne; K. E. K. Coppin; J. S. Dunlop; D. Farrah; M. Jarvis; M. J. Michalowski; M. Page; D. J. B. Smith; A. M. Swinbank; M. Symeonidis; P. P. Van der Werf
texts
eye 14
favorite 0
comment 0
We study the 850um emission in X-ray selected AGN in the 2 sq-deg COSMOS field using new data from the SCUBA-2 Cosmology Legacy Survey. We find 19 850um bright X-ray AGN in a high-sensitivity region covering 0.89 sq-deg with flux densities of S850=4-10 mJy. The 19 AGN span the full range in redshift and hard X-ray luminosity covered by the sample - 0.71 X-ray AGN - S850=0.71+/-0.08mJy. We explore trends in the stacked 850um flux densities with redshift, finding no evolution in the average cold...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1509.00018
6
6.0
Jun 29, 2018
06/18
by
Liang Wang; Aaron A. Dutton; Gregory S. Stinson; Andrea V. Macciò; Thales Gutcke; Xi Kang
texts
eye 6
favorite 0
comment 0
We use the NIHAO galaxy formation simulations to make predictions for the baryonic budget in present day galaxies ranging from dwarf to Milky Way masses. The sample is made of 88 independent high resolution cosmological zoom-in simulations. NIHAO galaxies reproduce key properties of observed galaxies, such as the stellar mass vs halo mass and cold gas vs stellar mass relations. Thus they make plausible predictions for the baryon budget. We present the mass fractions of stars, cold gas ($T...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1601.00967
4
4.0
Jun 29, 2018
06/18
by
Nicolas Peretto; Mathilde Gaudel; Fabien Louvet; Gary A. Fuller; Alessio Traficante; Ana Duarte-Cabral
texts
eye 4
favorite 0
comment 0
The role played by gravity in the transfer of interstellar matter from molecular cloud scales to protostellar scales is still highly debated. Only detailed studies on the kinematics of large samples of star-forming clouds will settle the issue. We present new IRAM 30m observations of a sample of 27 infrared dark clouds covering a large range of sizes, masses, and aspect ratios. Preliminary results suggest that gravity is regulating the dynamical evolution of these clouds on a couple of parsec...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1601.07956
3
3.0
Jun 29, 2018
06/18
by
Elisa Toloba; Biao Li; Puragra Guhathakurta; Eric Peng; Laura Ferrarese; Patrick Cote; Eric Emsellem; Stephen Gwyn; Hongxin Zhang; Alessandro Boselli; Jean-Charles Cuillandre; Andres Jordan; Chengze Liu
texts
eye 3
favorite 0
comment 0
We analyze the kinematics of six Virgo cluster dwarf early-type galaxies (dEs) from their globular cluster (GC) systems. We present new Keck/DEIMOS spectroscopy for three of them and reanalyze the data found in the literature for the remaining three. We use two independent methods to estimate the rotation amplitude (Vmax) and velocity dispersion (sigma_GC) of the GC systems and evaluate their statistical significance by simulating non-rotating GC systems with the same number of GC satellites...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1603.01617
5
5.0
Jun 29, 2018
06/18
by
Todor V. Veltchev; Sava Donkov; Ralf S. Klessen
texts
eye 5
favorite 0
comment 0
We present a model for describing the general structure of molecular clouds (MCs) at early evolutionary stages in terms of their mass-size relationship. Sizes are defined through threshold levels at which equipartitions between gravitational, turbulent and thermal energy $|W| \sim f(E_{\rm kin} + E_{\rm th})$ take place, adopting interdependent scaling relations of velocity dispersion and density and assuming a lognormal density distribution at each scale. Variations of the equipartition...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1603.08441
4
4.0
Jun 29, 2018
06/18
by
F. S. Liu; Dongfei Jiang; Yicheng Guo; David C. Koo; S. M. Faber; Xianzhong Zheng; Hassen M. Yesuf; Guillermo Barro; Yao Li; Dingpeng Li; Weichen Wang; Shude Mao; Jerome J. Fang
texts
eye 4
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comment 0
The rest-frame UV-optical (i.e., NUV-B) color index is sensitive to the low-level recent star formation and dust extinction, but it is insensitive to the metallicity. In this Letter, we have measured the rest-frame NUV-B color gradients in ~1400 large ($\rm r_e>0.18^{\prime\prime}$), nearly face-on (b/a>0.5) main-sequence star-forming galaxies (SFGs) between redshift 0.5 and 1.5 in the CANDELS/GOODS-S and UDS fields. With this sample, we study the origin of UV-optical color gradients in...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1604.05780
5
5.0
Jun 30, 2018
06/18
by
Xiawei Wang; Abraham Loeb
texts
eye 5
favorite 0
comment 0
A population of intermediate-mass black holes (BHs) is predicted to be freely floating in the Milky Way (MW) halo, due to gravitational wave recoil, ejection from triple BH systems, or tidal stripping in the dwarf galaxies that merged to make the MW. As these BHs traverse the gaseous MW disk, a bow shock forms, producing detectable radio and mm/sub-mm synchrotron emission from accelerated electrons. We calculate the synchrotron flux to be $\sim \rm 0.01-10\, mJy$ at GHz frequency, detectable by...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1402.5975
10
10.0
Jun 30, 2018
06/18
by
A. V. Mosenkov; N. Ya. Sotnikova; V. P. Reshetnikov
texts
eye 10
favorite 0
comment 0
We analyzed several basic correlations between structural parameters of galaxies. The data were taken from various samples in different passbands which are available in the literature. We discuss disc scaling relations as well as some debatable issues concerning the so-called Photometric Plane for bulges and elliptical galaxies in different forms and various versions of the famous Kormendy relation. We show that some of the correlations under discussion are artificial (self-correlations), while...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1403.7555
5
5.0
Jun 30, 2018
06/18
by
Brett A. McGuire; P. Brandon Carroll; James L. Sanders; Susanna L. Widicus Weaver; Geoffrey A. Blake; Anthony J. Remijan
texts
eye 5
favorite 0
comment 0
The results of a Caltech Submillimeter Observatory (CSO) search for $l$-C$_3$H$^+$, first detected by Pety et al. (2012) in observations toward the Horsehead photodissociation region (PDR), are presented. A total of 39 sources were observed in the 1 mm window. Evidence of emission from $l$-C$_3$H$^+$ is found in only a single source - the Orion Bar PDR region, which shows a rotational temperature of 178(13) K and a column density of 7(2) x $10^{11}$ cm$^{-2}$. In the remaining sources, upper...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1405.7057
6
6.0
Jun 30, 2018
06/18
by
Georgina Coldwell; Sol Alonso; Fernanda Duplancic; Maren Hempel; Valentin D. Ivanov; Dante Minniti
texts
eye 6
favorite 0
comment 0
Suzaku and Chandra X-ray observations detected a new cluster of galaxies, Suzaku J1759-3450, at a redshift z=0.13. It is located behind the Milky Way, and the high Galactic dust extinction renders it nearly invisible at optical wavelengths. We attempt here to confirm the galaxy cluster with near-infrared imaging observations, and to characterize its central member galaxies. Images from the VVV survey were used to detect candidate member galaxies of Suzaku J1759-3450 within the central region of...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1407.0262
5
5.0
Jun 30, 2018
06/18
by
C. Gonzalo Díaz; Emma V. Ryan-Weber; Jeff Cooke; Yusei Koyama; Masami Ouchi
texts
eye 5
favorite 0
comment 0
The flow of baryons to and from a galaxy, which is fundamental for galaxy formation and evolution, can be studied with galaxy-metal absorption system pairs. Our search for galaxies around CIV absorption systems at $z\sim5.7$ showed an excess of photometric Lyman-$\alpha$ emitter (LAE) candidates in the fields J1030+0524 and J1137+3549. Here we present spectroscopic follow-up of 33 LAEs in both fields. In the first field, three out of the five LAEs within 10$h^{{-}1}$ projected comoving Mpc from...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1412.6694
12
12
Jun 26, 2018
06/18
by
F. Pozzi; F. Calura; C. Gruppioni; G. L. Granato; G. Cresci; L. Silva; L. Pozzetti; F. Matteucci; G. Zamorani
texts
eye 12
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comment 0
We present a backward approach for the interpretation of the evolution of the near-infrared and the far-infrared luminosity functions across the redshift range 02 can be explained as progenitors of local spheroids caught during their formation. We also test the effects of mass downsizing by dividing the spheroids into three populations of different present-day stellar masses. The results obtained in this case confirm the validity of our approach, i.e. that the bulk of proto-spheroids can be...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1502.03686
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16
Jun 27, 2018
06/18
by
Graziella di Tullio Zinn; Robert Zinn
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eye 16
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The whole Sloan Digital Sky Survey (SDSS, 14,555 deg^2 has been searched for intergalactic globular clusters (IGCs) in the Local Group (LG). Using optical, infrared, and ultraviolet photometric selection criteria and photometric redshifts, the 2.1x10^8 of objects in the SDSS Galaxy Catalogue were reduced to only 183,791 brighter than r_o = 19 that might be GCs. Visual examination of their SDSS images recovered 84 percent of the confirmed GCs in M31 and M33 and yielded 17 new GC candidates, 5 of...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1503.02963
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12
Jun 27, 2018
06/18
by
Chen Hu; Pu Du; Kai-Xing Lu; Yan-Rong Li; Fang Wang; Jie Qiu; Jin-Ming Bai; Shai Kaspi; Luis C. Ho; Hagai Netzer; Jian-Min Wang
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eye 12
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This is the third in a series of papers reporting on a large reverberation-mapping campaign aimed to study the properties of active galactic nuclei (AGNs) with high accretion rates. We present new results on the variability of the optical Fe II emission lines in 10 AGNs observed by the Yunnan Observatory 2.4m telescope during 2012--2013. We detect statistically significant time lags, relative to the AGN continuum, in nine of the sources. This accurate measurement is achieved by using a...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1503.03611
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14
Jun 27, 2018
06/18
by
Colin T. Slater; Eric F. Bell; Nicolas F. Martin; Erik J. Tollerud; Nhung Ho
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eye 14
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We present the results of a deep study of the isolated dwarf galaxies Andromeda XXVIII and Andromeda XXIX with Gemini/GMOS and Keck/DEIMOS. Both galaxies are shown to host old, metal-poor stellar populations with no detectable recent star formation, conclusively identifying both of them as dwarf spheroidal galaxies (dSphs). And XXVIII exhibits a complex horizontal branch morphology, which is suggestive of metallicity enrichment and thus an extended period of star formation in the past....
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1505.02161
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7.0
Jun 30, 2018
06/18
by
Kareem El-Badry; Daniel R. Weisz; Eliot Quataert
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eye 7
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We use Monte Carlo simulations to explore the statistical challenges of constraining the characteristic mass ($m_c$) and width ($\sigma$) of a lognormal sub-solar initial mass function (IMF) in Local Group dwarf galaxies using direct star counts. For a typical Milky Way (MW) satellite ($M_{V} = -8$), jointly constraining $m_c$ and $\sigma$ to a precision of $\lesssim 20\%$ requires that observations be complete to $\lesssim 0.2 M_{\odot}$, if the IMF is similar to the MW IMF. A similar...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1701.02347
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5.0
Jun 30, 2018
06/18
by
Marc S. Seigar; Benjamin L. Davis; Joel Berrier; Daniel Kennefick
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eye 5
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We investigate the use of spiral arm pitch angles as a probe of disk galaxy mass profiles. We confirm our previous result that spiral arm pitch angles (P) are well correlated with the rate of shear (S) in disk galaxy rotation curves. We use this correlation to argue that imaging data alone can provide a powerful probe of galactic mass distributions out to large look-back times. We then use a sample of 13 galaxies, with Spitzer 3.6-$\mu$m imaging data and observed H$\alpha$ rotation curves, to...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1409.6667
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6.0
Jun 30, 2018
06/18
by
G. Leloudas; S. Schulze; T. Kruehler; J. Gorosabel; L. Christensen; A. Mehner; A. de Ugarte Postigo; R. Amorin; C. C. Thoene; J. P. Anderson; F. E. Bauer; A. Gallazzi; K. G. Helminiak; J. Hjorth; E. Ibar; D. Malesani; N. Morrell; J. Vinko; J. C. Wheeler
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eye 6
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Superluminous supernovae (SLSNe) are very bright explosions that were only discovered recently and that show a preference for occurring in faint dwarf galaxies. Understanding why stellar evolution yields different types of stellar explosions in these environments is fundamental in order to both uncover the elusive progenitors of SLSNe and to study star formation in dwarf galaxies. In this paper, we present the first results of our project to study SUperluminous Supernova Host galaxIES, focusing...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1409.8331
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6.0
Jun 30, 2018
06/18
by
Chun Ly; Jane Rigby; Michael Cooper; Renbin Yan
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eye 6
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We report on the discovery of 28 $z\approx0.8$ metal-poor galaxies in DEEP2. These galaxies were selected for their detection of the weak [OIII]$\lambda$4363 emission line, which provides a "direct" measure of the gas-phase metallicity. A primary goal for identifying these rare galaxies is to examine whether the fundamental metallicity relation (FMR) between stellar mass, gas metallicity, and star formation rate (SFR) holds for low stellar mass and high SFR galaxies. The FMR suggests...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1412.1834
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5.0
Jun 30, 2018
06/18
by
M. Orienti; F. D'Ammando; M. Giroletti; G. Giovannini; F. Panessa
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eye 5
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Despite targets of many multiwavelength campaigns, the main physical processes at work in AGN are still under debate. In particular the origin of the radio emission and the mechanisms involved are among the open questions in astrophysics. In the radio-loud AGN population the radio emission is linked to the presence of bipolar outflows of relativistic jets. However, the large majority of the AGN population do not form powerful highly-relativistic jets on kpc scales and are characterized by radio...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1412.5846
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6.0
Jun 30, 2018
06/18
by
J. Wagg; E. Da Cunha; C. L. Carilli; F. Walter; M. Aravena; I. Heywood; J. Hodge; E. Murphy; D. Riechers; M. Sargent; R. Wang
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eye 6
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The Square Kilometre Array will be a revolutionary instrument for the study of gas in the distant Universe. SKA1 will have sufficient sensitivity to detect and image atomic 21 cm HI in individual galaxies at significant cosmological distances, complementing ongoing ALMA imaging of redshifted high-J CO line emission and far-infrared interstellar medium lines such as [CII] 157.7 um. At frequencies below ~50 GHz, observations of redshifted emission from low-J transitions of CO, HCN, HCO+, HNC, H2O...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1412.5793
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6.0
Jun 30, 2018
06/18
by
ChangHoon Hahn; Michael R. Blanton; John Moustakas; Alison L. Coil; Richard J. Cool; Daniel J. Eisenstein; Ramin A. Skibba; Kenneth C. Wong; Guangtun Zhu
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eye 6
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We investigate the effects of galaxy environment on the evolution of the quiescent fraction ($f_\mathrm{Q}$) from z =0.8 to 0.0 using spectroscopic redshifts and multi-wavelength imaging data from the PRIsm MUlti-object Survey (PRIMUS) and the Sloan Digitial Sky Survey (SDSS). Our stellar mass limited galaxy sample consists of ~14,000 PRIMUS galaxies within z = 0.2-0.8 and ~64,000 SDSS galaxies within z = 0.05-0.12. We classify the galaxies as quiescent or star-forming based on an evolving...
Topics: Astrophysics of Galaxies, Astrophysics
Source: http://arxiv.org/abs/1412.7162
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12
Jun 26, 2018
06/18
by
M. S. Miranda; B. A. Macfarlane; B. K. Gibson
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eye 12
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The spatial and temporal relationships between stellar age, kinematics, and chemistry are a fundamental tool for uncovering the physics driving galaxy formation and evolution. Observationally, these trends are derived using carefully selected samples isolated via the application of appropriate magnitude, colour, and gravity selection functions of individual stars; conversely, the analysis of chemodynamical simulations of galaxies has traditionally been restricted to the age, metallicity, and...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1502.00444
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26
Jun 27, 2018
06/18
by
A. Moretti; D. Bettoni; B. M. Poggianti; G. Fasano; J. Varela; M. D'Onofrio; B. Vulcani; A. Cava; J. Fritz; W. J. Couch; M. Moles; P. Kjærgaard
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eye 26
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Using V band photometry of the WINGS survey, we derive galaxy luminosity functions (LF) in nearby clusters. This sample is complete down to Mv=-15.15, and it is homogeneous, thus allowing the study of an unbiased sample of clusters with different characteristics. We constructed the photometric LF for 72 out of the original 76 WINGS clusters, excluding only those without a velocity dispersion estimate. For each cluster we obtained the LF for galaxies in a region of radius=0.5 x r200, and fitted...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1506.01201
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12
Jun 28, 2018
06/18
by
S. Meneses-Goytia; R. F. Peletier; S. C. Trager; A. Vazdekis
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eye 12
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We present unresolved single stellar population synthesis models in the near-infrared (NIR) range. The extension to the NIR is important for the study of early-type galaxies, since these galaxies are predominantly old and therefore emit most of their light in this wavelength range. The models are based on a library of empirical stellar spectra, the NASA infrared telescope facility (IRTF) spectral library. Integrating these spectra along theoretical isochrones, while assuming an initial mass...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1506.07183
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20
Jun 28, 2018
06/18
by
J. Scharwächter; M. A. Dopita; P. Shastri; R. Davies; L. Kewley; E. Hampton; R. Sutherland; P. Kharb; J. Jose; H. Bhatt; S. Ramya; C. Jin; J. Banfield; I. Zaw; S. Juneau; B. James; S. Srivastava
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eye 20
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The Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7) is a targeted survey probing the narrow-line regions (NLRs) of a representative sample of ~140 nearby (z
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1507.01952
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7.0
Jun 29, 2018
06/18
by
Carl J. Grillmair; Jeffrey L. Carlin
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eye 7
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Recent years have seen the discovery of an ever growing number of stellar debris streams and clouds. These structures are typically detected as extended and often curvilinear overdensities of metal-poor stars that stand out from the foreground disk population. The streams typically stretch tens of degrees or more across the sky, even encircling the Galaxy, and range in heliocentric distance from 3 to 100 kpc. This chapter summarizes the techniques used for finding such streams and provides...
Topics: Astrophysics, Astrophysics of Galaxies
Source: http://arxiv.org/abs/1603.08936
